A Intraluminal Duodenal Diverticulum(IDD) is a rare congenital anomaly in adult, which presents as a mucosal pouch within the second portion of the duodenum and causes varying degrees of obstructive symptoms. The true pathogenesis of the lesion is still unknown, but it provably results from ballooning of a congenital duodenal diaphragm with prolonged peristalsis. A pear-shaped intraluminal pouch resembling a barium-filled "wind sock" surrounded by a radiolucent halo, partially obstructing the duodenal lumen is the classic and diagnostic radiologic appearance. Proper identification of the papilla of Vater is important since this structure is often adjacent to the diverticulum. A case of IDD which occured in a 15-year-old boy with intermittent upper abdominal pain, nausea, and vomiting for 2 years is reported with review of the literatures.teratures.